High intensity spot and flood lamps, also known as luminaries, using light emitting diodes (LEDS) are now widely used in many different lighting applications. Like its incandescent and fluorescent counterparts, this type of high intensity lighting can efficiently illuminate objects and are used in landscaping, security, industrial, hospitality, household and entertainment settings. As compared to a conventional incandescent bulb, LEDs have a long life span and an excellent anti-shock performance in high power applications. Moreover, high luminance LED lighting can be more easily manufactured in many differing shapes, sizes, brightness and efficiency levels to fit a specific need. LED luminaries are more commonly available in all form factors ranging from the standard A19 household bulb to R150 bulbs used in street light and industrial locations.
One drawback in using high-luminance LED lighting is that it emits a high amount of heat. When used in large groups in a limited space, there are often difficulties in designing and applying the LED as a light source. Since the LED is a semiconductor device, if the heat dissipation efficiency of the luminary is low, the life span of the LEDs will be shortened. Obviously, this is undesirable since shorting the LED's life would defeat one of its primary benefits of using this type of light source. In order to maintain the life of the LED at expected levels, the LED die is generally kept below approximately 125 degrees Celsius. Thus, designing an LED luminary so that the LED die is maintained at a low temperature can be very challenging.
As seen in U.S. Pat. No. 8,089,085 issued Jan. 3, 2012 to Shi, heat pipes are often mounted at the sides of the LED die. The heat pipes and LED both connect to an aluminum substrate at the back of the light so that heat generated from the LEDs can more easily be dissipated. Since the heat is transferred through the heat pipes, this heated air within the pipes can then be further transferred to a heat dissipation cover. Although this type of secondary heat dissipation works to dissipate heat to the external air, there are also more effective ways in lowering heat generated by the LEDs to an acceptable level.
Further, prior art FIG. 1 illustrates a parabolic aluminized reflector (PAR) style bulb assembly 100 using LEDs where the bulb assembly has a potted base 101 that works to house an LED power supply driver 103. The base 101 includes a socket 105 that is used to connect within a threaded female AC connection for supplying power to the driver 103. A heat sink base 105 is attached to conical housing 107, which has a substantially truncated conical shape. The conical housing 107 is open at both ends and has a wide opening at its top end 109 for allowing insertion of a heat sink disk 111. The disk 111 includes one or more holes 113 substantially at its center for allowing wire conductors (not shown) originating at driver 103 to extend therethrough. These wire conductors pass though the disk 111 and are used to power an LED light source 115. The LED light source 115 is positioned centrally within a circular housing 117 and includes one or more LED die (not shown) that are used for connecting a plurality of LED semiconductor devices. When assembled, the circular housing 117 is mechanically connected with both the conical housing 107 and heat sink disk 111 for thermally conducting heat away from the LED light source 115. When used outdoors, these heat sink components may also be hermetically sealed for preventing moisture or other contamination from entering the inside of the heat sink assembly.
A problem associated with this type of LED lighting assembly is the complex mechanical nature of housing having various components and pieces that must be separately manufactured and assembled. Those skilled in the art will recognize that other more efficient lighting designs are possible for more effectively removing heat while still maintaining a low manufacturing cost.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.